估計你搞錯了一個概念

對於配偶的情形是指: 主申請人在485批準之前如和男朋友或女朋友結婚, 可以在485批準之前遞交follow-join-in,讓其配偶同時拿到綠卡. 但一旦485已經批了, 一切都晚了.

而對於子女根本不存在這個問題. 樓主的孩子在485批準之前就是他的孩子. 可惜他在此之前根本沒有替孩子申請. 隻要他在此之前申請了,there is a substantial advantage to having the dependent obtain the Green Card based upon the principal I-485 applicant's case. The alternative will to file a relative petition and then have to wait approximately 4 to 6 years just waiting for the priority date to become current!